1. Field of the Invention
The present invention relates to a storing structure for oil for lubrication of engine parts. More particularly, to an oil storing device suitable for oil drainage and an engine having the oil storing device.
2. Description of Background Art
In a crankcase structure of an engine to be mounted on a vehicle such as an automobile is known wherein an oil pan for storing engine oil is located below a crankshaft. The engine oil stored in the oil pan is supplied to a crankshaft system and a cam system to lubricate the required sliding parts. Thereafter, the oil is next circulated to be returned to the oil pan. See, for example, Japanese Patent Laid-open No. 2006-183516.
Usually, the height of the crankshaft, the capacity of the oil pan, the amount of engine oil, etc. are suitably set so that the oil level of the engine oil in the oil pan is lower than the lowermost end of a locus of rotation of the crankshaft system.
In Japanese Patent Laid-open No. 2000-328921, a dry sump lubrication device for an engine is described with a dedicated oil tank. In this dry sump lubrication device, the oil tank is connected through any means such as a pipe to a lower portion of the engine. A dedicated drain bolt is provided at the lower portion of the engine, and the oil tank is also provided with a drain bolt. In supplying oil into the engine, the oil is directly poured into the oil tank.
In the structure disclosed in Japanese Patent Laid-open No. 2006-183516, the dedicated oil pan must be provided and it has a structure of almost covering the lower portion of the engine. In draining the oil, an oil receptacle is preliminarily set below a dedicated drain bolt, and the drain bolt is next removed. In this oil draining operation, a special tool for removing the drain bolt is required and attention must be paid so as not to drop the drain bolt into the oil receptacle. Thus, this oil draining operation is troublesome. Naturally, a work space for this operation is required and waste oil disposal after draining the oil is also required. Further, in this oil draining operation, the work space, the engine itself, and the operator are soiled with the oil in most cases.
Further, an oil filler port must be provided separately as is well known in the art. More specifically, from the viewpoint of the engine structure, the oil filler port is separate from an oil drain port, and it is presently impossible to eliminate these ports and thereby reduce the number of parts detachably mounted to the engine.
In the structure disclosed in Japanese Patent Laid-open No. 2000-328921, the position of an oil pan can be changed by adopting the dry sump lubrication. Accordingly, as compared with the structure disclosed in Japanese Patent Laid-open No. 2006-183516, the workability in the oil draining operation appears to be improved. However, the number of man-hours of the oil draining operation in the structure disclosed in Japanese Patent Laid-open No. 2000-328921 is the same as that in the structure disclosed in Japanese Patent Laid-open No. 2006-183516. More specifically, a special tool is required in draining the oil. Further, any work space accepted to be soiled with the oil is required and the problem that the operator is soiled with the oil still remains.